A variety of quill spindles for performing machining operations are known. In general, quill spindles include a motor that rotates a tool spindle (e.g. a drill spindle), and a feed unit that advances the rotating tool spindle toward a workpiece. Quill spindles for drilling may be used in cooperation with a clamping assembly that securely clamps the workpiece and stabilizes the drill spindle during drilling operations.
There are a number of existing drill spindles with quill feed. The small compact units typically use non-programmable hydraulic feed control, while others use a leadscrew feed mechanism with a drive axis that is parallel to, but offset from, a drilling axis of the drill spindle. More specifically, either the motor is offset with a belt or gearing transferring power from the motor to the leadscrew, or the entire feed system is offset with the spindle attached to a feed axis powered slide.
Although desirable results have been achieved using prior art drill spindles with quill feed, there is room for improvement. For example, to provide repeatable countersink depth precision, relatively rigid systems are required. Existing drill spindles with quill feed that provide the desired rigidity, however, are relatively bulky and heavy, and are incompatible with some types of clamping systems. Therefore, novel drill spindles with quill feed that provide the desired rigidity and that are lighter and less bulky than the prior art systems would have utility.